1. Field of the Invention
The present invention relates to a control device for an image processing apparatus or an image forming apparatus.
2. Related Background Art
Recent progress in electronics is particularly marked in the fields of office automation, factory automation, laboratory automation, etc., and such progress can be attributed to a skilful combination of electronics and mechanisms. Naturally it is basically supported by the amalgamation of ever-progressing semiconductor integration and computer technology, since inexpensive mass production has to rely on the use of system large-scale integrated circuits. However, there is still much to be improved in the mechanisms, particularly in the interface portion between analog-functioning components and digital control electronics. In the current state of technology, most digital control electronics only perform simple on-off control for analog components. For this reason such analog components still have complex control systems of their own, and the potential of the digital control electronics is not fully exploited in such interface systems. Consequently there still exists an unnecessary cost associated with such interface systems, which has to be borne by the users.
Presently such digital control electronics are mostly microcomputers or microcontrollers which are one-chip microcomputers incorporating memories and I/O ports. For controlling such analog components, there is already known a one-chip microcomputer incorporating an A/D converter on the same chip. Also there is announced a controller incorporating a counter/timer, an A/D controller, and an interface for PWM output/display devices such as an LCD interface driver in addition to a CPU and a memory. However these conventional devices are simple large-scale integrated circuits in which already known components are combined, and are unable to eliminate the above-mentioned drawbacks particularly present in the interface portion between analog-functioning components and digital control electronics, as many analog components will contain their own control units therein due to the requirement for proper processing speed and the complexity inherent in their control. Consequently, equipment involving analog components is associated with a higher cost.
Particularly, equipment employing a large number of analog components, such as a copying machine, has inevitably suffered from an elevated manufacturing cost.